package org.apache.commons.graph.algorithms.spanning

import org.apache.commons.graph.Graph
import org.apache.commons.graph.Mapper

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

interface SpanningWeightedEdgeMapperBuilder<V, WE> {
    fun <W> whereEdgesHaveWeights(weightedEdges: Mapper<WE, W>): SpanningTreeSourceSelector<V, W, WE>
}


/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

class DefaultSpanningWeightedEdgeMapperBuilder<V, WE>(
    private val graph: Graph<V, WE>
) : SpanningWeightedEdgeMapperBuilder<V, WE> {
    override fun <W> whereEdgesHaveWeights(weightedEdges: Mapper<WE, W>): SpanningTreeSourceSelector<V, W, WE> {
        //var weightedEdges = weightedEdges
        //weightedEdges = Assertions.checkNotNull(weightedEdges, "Function to calculate edges weight can not be null.")
        return DefaultSpanningTreeSourceSelector(graph, weightedEdges)
    }
}

fun <V, WE, G : Graph<V, WE>> G.minimumSpanningTree(): SpanningWeightedEdgeMapperBuilder<V, WE> = DefaultSpanningWeightedEdgeMapperBuilder(this)

fun <V, WE, G : Graph<V, WE>,W> G.minimumSpanningTree(weightedEdges: Mapper<WE, W>) = minimumSpanningTree().whereEdgesHaveWeights(weightedEdges)